One means of using coal in a relatively pollution-free manner to generate power is to burn the coal in a gasifier, producing a low BTU gas which can be used in a combined cycle, or a gas turbine and a steam generator, both of which drive electrical generators. In order to maximize efficiency of a combined cycle, it is necessary to utilize as much of the heat at the highest thermal level in the flue gases leaving the gasifier, steam generator, and the gas turbine as possible.